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Patented Jan. 9, 1923,

UNITED stares GOLIIN Gr. ITINK, 0F YOI IIKTGHIFJ, N1

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No Drawing.

To all whom it may concern:

Be it known that 1, Conan Gr. Finn, a citizen of the United States, residing at Yonkers, in the county oi. l i estchester, lfltate of New York, have invented certain. new and useful Improvements in lillectrodeposi' tion oi Copper; and I do hereby declare the following to be a full, clear, and exact description ot the invention, such. as will enable others skilled in the art to which it ap JGI'titiIlS to make and use the same.

This invention relates to improvements in the electrodeposition of copper with insoluble anodes; and more particularly to the electro-deposition of copper from copper sulfate electrolytes conta'inin iron and copper sulfate electrolytes containing chloridi-xs and nitrates.

According to the present inventiini, the electro-deposition oil. copper troi'u coppercontaiining electrolytes is carried out with an insoluble anode, i. e., an anode h ighly resistant to anodic disintegration, which is made of an alloy composed for the most part ofcopper.

The invention is based upon the discovery that by using an anode consisting principally oi copper, silicon and lead, the electro-deposition of copper can be carried out with a remarkably low corrosion loss or disintegration of the anode, without objection able contamination oil: the electrolyte, with low anodic poti-antial and low power consumption, with high current clliciency, etc.

'lhe insoluble anodes which lf use in the sent invention are composed for the most part oil. copper, and their most important constituents are co pcr, silicon and lead. In addition, I have found it advantageous to have present in the anode small amounts of certain other elements or materials, particularly manganese. lhe anode may thus be made of an alloy containing from about -15 to 20% of silicon, from to 10% of lead, from 2 to 15% of manganese, and the balance copper; although small amounts of other elements may advantageously be present. Elements such as tin, iron, tungsten, chromium, nickel, etc, may thus, under certain conditions, be our objectionable in the anode, or may even be advantageous therein,

One preferred way of melting the anode is to use an alloy of lead with an alkali process oi? the pr Application tiled lttareh 1t}, 'lttl.

earth metal, such as calcium or barium, and to combine this lead alloy, in a molten state, with an alloy of copper and silicon. [inother advantageous mode of malinp; the alloy to add the lead in the form of lead. sulfide or galenato a molten. bath. containing copper and silicon. 'l.he specific gravity oi? the galena is such that the lead can be.

*l l'tJll'l the electrolyte.

.l' have found that such anodes can be used to particular advantage in the electrodeposition oi? copper from copper sulfate electrolytes containing chlorides and nitrates. and that, even with such electrolytes, the electro--deposition can be carried out with low anodic disintegration. The electin-deposition can, moreover, be carried out without objectionable contamination of the electrolyte by such slight disintegration oi. the anode as may talre place during prolonged use, inasmuch as coppersul'late is the principal metallic salt going into solution as the result ct such disintegra on.

it is a l' l'lt'lllltal chars.cteiist'c advantage oi the invention, that the ehwti'o-di-i iosition can he carried out with low :ine'ic inden tial, and with high current ell my and cm'nacipient t-iilllllp; inv power, pa'iticldarly in copper sultate electrolytes containing; iron, which is usually present to a greater or less extent in copper sulfate solutions result ing from the commercial leaching); of ore. l have found, for example, that the electro deposition of copper from copper sulfate electrolytes containing nitrates and chlorides when operating at a current density of around 15 to 20 amperes per so. it. oi anode surface, can be carried out with an anode potential as low as from 2.5 to 92, volts, and with an anode loss as low as the elcctro-deposited copper.

'llhe improved process of the present inrei'itiini is of particular advantage in the electro-deposition oi" copper from such 1% or less of copper sulfate electrolytes, containing chlorides and nitrates. The proces of the invention is also of particular value in the electro deposition of copper from copper sulfate electrolytes resulting from the leaching of ores and which usually contain iron. in appreciable amount. For example, the leaching of an oxidized or roasted copper ore can be carried out with a dilute sulfuric acid solution and the resulting copper sulfate solution, also containing more or less llOIl, can be subjected to electro-deposition, according to the present invention, for the electrodeposition of copper therefrom. The copper'may thus be electro-deposited from the solution toa greater or less extent, with resulting increase of the electrolyte in acidity, and the resulting electrolyte, without complete removal of copper therefrom, can be'used for the leaching of further amounts of ore. That is, the leaching and electrolytic operations may be carried out as cyclic operations with recirculation of the electrolyte, and its'successive use for leaching and for electro-deposition of copper therefrom.

Heretofore in cyclic operations, where copper is leached from its ores, and the copper deposited electrolytically from the resulting solution, with recirculation and reuseof the electrolyte, lead and ferro-silicon anodes have been used as the so-called insoluble anodes. The present invention has "the advantage over the use of ferro-silicon anodes that a normally lower voltage can be used andsubstantially no iron is introduced into the electrolyte by corrosion of the anode, whereas with ferro-silicon anodes a very considerable contamination of the electrolyte by introduction of iron takes place,and'th1s contamination increases proressively Wlth recirculation of the electroe. Byavoiding such introduction of iron from the anode, the present invention materially decreases the cost of maintaining alow iron content in the electrolyte, since the electrolyte can be used for longer periods of time without requiring purification, thus saving in the cost of purification, reducing the acid lost with the impure electrolyte or in purifying the electrolyte, and reducing the amount of impure copper formed. As

compared with the use of a lead anode, the

present invention presents the advantage of increased efficiency, particularly in electro 'lytes containing iron, inasmuch as lead anodes give extremely low current efiiciency with such electrolytes unless special precautions are taken to keep the iron in the ferrous condition. The present invention precents the further advantages that the anode loss is materially less than with either ferrosilicon or lead anodes, with certain electrolytes, particularly copper sulfate electrolytes containing chlorides and nitrates.

Owing to the relatively low cost of the anodes themselves in the first instance, and their resistance to breakage during handling and ordinary use, as well as their resistance to anodic disintegration, the process can he carried out for long periods of time, with resulting low cost of operation for the anodes, as well as with economy of opera tion in low voltage and power consumption and high current efliciency.

I do not claim herein the anode itself, which I make use of in the process of the present invention, as this forms the subjectmattcr of a co-pending application, rerial No. 446,070, filed February 18, 1921.

I claim:

1. The improvement in the electrodeposition of copper which comprises electrolytically depositing copper from a copper sulfate electrolyte with an anode com .ed for the most part of copper and. high y resistant to anodic disintegration.

The improvement in the electrodqmsh tion of copper which comprises electrolytically depositing copper from a copper sulfate electrolyte with an anode composed principally of copper and silicon and highly resistant to anodic disintegration.

3. The in'iprovcment in the electrodeposition oi copper which comprises elcctrolyti Cally depositing copper from a copper sulfate electrolyte with an anode composed principally of copper and silicon and containing lead.

4. The improvement in the electrodeposition of copper which comprises electrolytt cally depositing copper from a copper sulfate electrolyte with an anode composed principally of copper and silicon and containin I lead and manganese.

5. The improvement in the electrodeposition of copper, which comprises electrolytically depositing copper from a copper sulfate electrolyte with an anode of an alloy composed for the most part of copper and of such resistance to anodic disintegration that the anode loss does not materially exceed 1% by Weight of the electrodqxisiteil copper.

6. The ii'nprovcment in the clectrodeposition of copper, which comprises electrolytically depositing copper from a copper sulfate electrolyte with an anode composed for the most part of copper and of such low anodic potential and resistance to anodic disintegration that the power consumption is relatively low and the anode loss less than about 1% by weight of the electrodeposited copper.

7 The improvement in the electrodeposition of copper, which comprises clectrolvtically depositing copper from a copper sulfate electrolyte with an anode composed principally of copper, silicon and lead and of. such low anodic potential and resistance to unodic disintegration that the power con- 1,441,508 tit slnnption is relatively low and the anode loss less than about lb by weight of the electrodeposited copper.

The improvement in the electrodeposition oi. copper which comprises electrolytically depositing copper from a copper sulfate electrolyte containing iron with an anode of an alloy composed for the most part of copper and highly resistant to anodic disintegration.

9. The improvement in the electrodeposition of copper, which comprises electrolytically depositing copper from a copper sulfate electrolyte containing iron with an anode composed principally oi copper silicon and lead and highly re intent to anodic disintegration.

1.0. The improvement in the electrodeposition of copper, which comprises electrolytically depositing copper from a copper sul- :tate electrolyte containing chlorides and nitrates with an anode of an alloy composed for the most part of copper and highly resistant to anodic disintegration.

11. The improvement in the electmdeposition of copper, Which comprises electrolytically depositing copper trom a copper snl fate electrolyte containing chlorides and nitrates With an anode composed principally of copper, silicon and lead and highly resist ant to anodic disintegration.

12. The improvement .in the electro-deposition of copper, which comprises electrolytically depositing copper from a copper sulfate electrolyte containing chlorides and nit ates with. an anode composed principally of copper and. silicon and containing; lead and tin, and highly resistant to anodic di integration.

13. The improvement in the e1ectro-deposition of copper, which comprises electrolytically depositing copper from a copper sultate electroylte containing iron with a anode composed principally oi copper and silicon and containing lead and tin.

M. The improvement in the electro-deposition of: copper, Which comprises electrolytically depositing copper from a copper sulfate electrolyte With an anode composed principally oi copper and silicon and containing lead and tin, and highly resistant to anodic disintegration.

In testimony whereof I aliii: my signature.

(lOllll l G; Fl'll'lt. 

